When i say energy gain i mean like energy gain from skills like Channeling, Ether Signet, basically the whole Inspiration Magic line. 1 problem with this healing exhaustion effect I see would be complete imbalance with Elemental Attunements. Not just Elemental Attunement, the other attunements too. Also, skills like Auspicious Incantation which give giant boosts of energy gain. Things like that could make Gale spammable or the Mind (Shock, Freeze, Burn) spells. I think a fraction of energy gain would be best for healing Exhaustion if that can even be done with Guild Wars.
I just really think there needs to be a way of managing Exhaustion other than making a whole skill, possibly elite, on your bar really situational.

